code: def test_render():
      assert (
          Style(color="red").render("foo", color_system=None) == "foo"
      )
      assert (
          Style(color="red", bgcolor="black", bold=True).render("foo")
          == "\x1b[1;31;40mfoo\x1b[0m"
      )
      assert Style().render("foo") == "foo"
  
imports: import pytest
  from rich import errors
  from rich.color import Color, ColorSystem, ColorType
  from rich.style import Style, StyleStack
label_desc: Use image node_id 15 for calling a global function with example usage: test_render() without return types